TABLE OF CONTENTS
15. Conclusions.. 15-1
15.1 Introduction.. 15-1
15.2 Air Quality.. 15-1
15.3 Noise.. 15-2
15.4 Water Quality.. 15-2
15.5 Waste Management
Implications.. 15-2
15.6 Land Contamination.. 15-2
15.7 Ecology.. 15-3
15.8 Hazard to Life.. 15-3
15.9 Landscape and
Visual. 15-3
15.10 Cultural Heritage.. 15-4
15.11 Overall Conclusion.. 15-4
15.
Conclusions
15.1.1.1
This EIA Report has provided an
assessment of the potential environmental impacts associated with the construction
and operation of the proposed Sai O Trunk Sewer SPS, based on the engineering
design information available at this stage.
The assessment has been conducted, in accordance with the EIA Study
Brief (No. ESB-281/2014) under the EIAO
for the Project and EIAO-TM, covering
the following environmental issues:
·
Air Quality Impact
·
Noise Impact
·
Water Quality Impact
·
Waste Management Implication
·
Land Contamination
·
Ecological Impact
·
Hazard to Life
·
Landscape and Visual Impact
·
Cultural Heritage Impact
15.1.1.2
The findings of this EIA report
have determined the likely nature and extent of environmental impacts predicted
to arise from the construction and operation of the Project. During the EIA process, environmental control
measures have been identified and incorporated into the planning and design of
the Project, to achieve compliance with environmental legislation and standards
during both the construction and operational phases. The Implementation Schedule listing the
recommended mitigation measures is presented in Section 13. An environmental
monitoring and audit (EM&A) programme has also
been developed. Details of the EM&A
requirements are provided in a standalone EM&A manual.
15.1.1.3
The assessment results for each
environmental aspect are summarised in the following sections.
15.2.1.1
Potential air quality impact
during construction phase would be fugitive dust generated from wind erosion of
the excavated areas and stockpiles, and dusty construction activities. With implementation of regular site watering
and good construction practices for dust minimisation, construction dust
impacts are not expected to be significant on the surrounding sensitive
receivers. Requirements of Air Pollution Control (Construction Dust)
Regulation and EPD’s Recommended
Pollution Control Clauses for Construction Contracts are proposed to be
incorporated into the contract.
15.2.1.2
Odour emission from the
proposed Sai O Trunk Sewer SPS would be the main concern during the operational
phase. Air ventilated from the enclosed
structure of the proposed SPS should be treated by deodorising unit with odour
removal efficiency of at least 99.5% in terms of target odour species, i.e. H2S
before discharge to the atmosphere. The
exhaust outlet of the deodorising unit would be located away from the nearby
air sensitive receivers as far as practicable, i.e. facing east of the Sai O
Trunk Sewer SPS. With incorporation of the proposed odour control measures in the design of the SPS, quantitative assessment
indicated the predicted odour concentrations at representative ASRs would
comply with respective EIAO-TM criterion of 5 OU, no adverse air quality impact
would be anticipated from the operation of the SPS.
15.3.1.1
The assessment for the
potential construction noise impact from the proposed Sai O Truck Sewer SPS has
been conducted. The assessment result indicated that the mitigated noise levels
at all NSRs would comply with the noise criteria set out in the EIAO-TM with proper implementation of
the proposed mitigation measures, including adoption of good site practices,
use of quiet PME, movable noise barriers / acoustic mats and proper scheduling
of noisy construction activities. No
adverse noise impact is anticipated during construction phase of the Project.
15.3.1.2
The noise impact associated
with the operation of the Project has been assessed based on the plant
inventory provided by the Project engineer at the time of the assessment. The assessment result indicated that the
predicted fixed plant noise levels at all representative NSRs would comply with
the noise criteria with proper implementation of the proposed mitigation
measures. No adverse noise impact is
anticipated during operational phase of the Project.
15.4.1.1
Key concerns of water quality
issues would be mainly related to the potential of construction run-off during
construction phase, and emergency sewage overflow / bypass from the SPS during
the operational phase. With incorporation of the precautionary design of the
SPS, proper implementation of the proposed mitigation measures and good site
practices, adverse water quality impact would not be expected during the
construction and operational phases.
15.5.1.1
The main waste types generated
from the construction phase would be C&D materials, chemical waste and general refuse. Waste management would be the
contractor’s responsibility to ensure that all wastes produced during the
construction of the Project are handled, stored and
disposed of in accordance with good waste management practices and EPD’s
regulations and requirements. The
recommended mitigation measures should form the basis of the site’s Waste Management
Plan to be developed by the Contractors at the construction stage. The main waste types generated from the
operation of the Project would be screenings.
Small quantities of chemical wastes are also anticipated. With implementation of the recommended
mitigation measures, adverse environmental impacts would not be anticipated
during construction and operational phases.
15.6.1.1
Based on the findings of desktop review and site walkover, no current or
historical potentially contaminating land uses / activities were identified within
the Project site and therefore adverse land contamination impact arising from the
construction and operation of the Project is not anticipated. No mitigation
measure is deemed necessary.
15.7.1.1
A total of 12 habitat types
were identified within the assessment area, including woodland, mixed woodland,
plantation, shrubland, grassland, developed area / wasteland, natural
watercourse, modified watercourse, mangrove, rocky shore, sandy shore and intertidal mudflat. The woodland, mixed woodland
and the intertidal habitats within the assessment area are considered to have
moderate ecological value while the other habitats are of low or low to
moderate ecological value. 6 flora and
19 fauna species of conservation importance were recorded in the assessment
area. The Project area is a shrubland of
low ecological as it is derived by recolonization of weedy vegetation and under
frequent disturbance. While a mammal species of conservation importance was
identified within the Project area in the previous survey, no species of
conservation importance was recorded in the recent survey.
15.8.1.1
The proposed sewage pumping station will be an unmanned station during
operation. The risks in the construction
and operation of the proposed Project associated with two high pressure town
gas pipelines and an offtake and pigging station were assessed. The societal risk level was in the ALARP
region. The results showed that both the individual risks and societal risks
comply with the Risk Guidelines given
in Annex 4 of the EIAO-TM.
15.8.1.2
The risks in the construction and operation of the proposed Project
associated with the Ma On Shan Water Treatment Works
(MOSWTW) was reviewed. The proposed development is relatively far away from the
MOSWTW, and it was concluded that risk to life from the MOSWTW was
insignificant which is not a key issue with respect to EIAO-TM.
15.9.1.1
During the construction phase,
the key sources of landscape and visual impacts would mainly due to the
construction of the proposed Sai O Trunk Sewer SPS including associated
temporary works and removal of existing vegetation. During construction, 21 nos. of existing
trees would be retained in-situ.
Nevertheless, 65 nos. of existing trees within the proposed works
boundary would be felled. To compensate the loss of greenery, 65 nos. of new trees
are proposed on-site for compensation.
To replenish the loss of greenery, vertical green wall and green roof
are also proposed. The scale of
development is considered medium as the works are localized and at low
level. Generally, there would not be any
potential blockage of view during construction. With the implementation of mitigation measures
including preservation of trees, compensatory tree planting, control of
night-time lighting glare, erection of decorative screening hoarding, careful
management of construction activities and facilities, as well as reinstatement
of temporarily disturbed landscape areas, no unacceptable residual landscape
and visual impacts from the construction of the Project would be anticipated.
15.9.1.2
During the operational phase,
the operation of the proposed Sai O Trunk Sewer SPS would be the key sources of
landscape and visual impacts. With the recommended mitigation measures
including proposed tree and shrub planting to soften the proposed SPS,
aesthetically pleasing design of the proposed SPS, as well as provision of
green roof and vertical greening, no unacceptable residual landscape and visual
impacts from the operation of the Project would be anticipated.
15.10.1.1 Based on detailed assessment, there is no direct or indirect impact
to cultural heritage from the construction or operation of the Project. Thus, no mitigation measure is required.
15.1.1.1
Overall, the EIA Report has
predicted that the Project would be environmentally acceptable with the
implementation of the recommended mitigation measures for construction and
operational phases. An EM&A programme has
been recommended to ensure the effectiveness of recommended mitigation measures.